Wednesday, June 3, 2015

A new paper in GRL by Xiaochun Zhang and Ken Caldeira works out how long it takes for the greenhouse forcing by CO2 to exceed the combustion warming by fossil fuels. The heat from burning fossil fuels is soon outpaced by the heat retained from putting the CO2 into the atmosphere, released when those fossil fuels were burnt.

The Earth warms both when fossil fuel carbon is oxidized to carbon dioxide and when greenhouse effect of carbon dioxide inhibits longwave radiation from escaping to space. Various important time scales and ratios comparing these two climate forcings have not previously been quantified. For example, the global and time-integrated radiative forcing from burning a fossil fuel exceeds the heat released upon combustion within 2 months.

Over the long lifetime of CO2 in the atmosphere, the cumulative CO2-radiative forcing exceeds the amount of energy released upon combustion by a factor >100,000. For a new power plant, the radiative forcing from the accumulation of released CO2 exceeds the direct thermal emissions in less than half a year. Furthermore, we show that the energy released from the combustion of fossil fuels is now about 1.71% of the radiative forcing from CO2 that has accumulated in the atmosphere as a consequence of historical fossil fuel combustion.

If we want to curb global warming we need to shift to energy sources that don't release greenhouse gases.

They found that the carbon dioxide-caused warming exceeds the amount of heat released by a lump of coal in just 34 days. The same phenomenon is observed in 45 days for an isolated incident of oil combustion, and in 59 days for a single instance of burning natural gas.

“Ultimately, the warming induced by carbon dioxide over the many thousands of years it remains in the atmosphere would exceed the warming from combustion by a factor of 100,000 or more,” Caldeira said.

For a power plant that is continuously burning, the warming caused by atmospheric carbon dioxide exceeded the heat released into the atmosphere by combustion in less than half a year–just three months for coal plants. With this kind of steady continuous combustion, it takes 95 days using coal, 124 days using oil, and 161 days using natural gas.

Caldeira explained: “If a power plant is burning continuously, within 3 to 5 months, depending on the type of power plant, the CO2 from the power plant is doing more to heat the Earth than the fires in its boiler. As time goes on, the rate of burning in the power plant stays the same, but the CO2 accumulates, so by the end of the year, the greenhouse gases will be heating the Earth much more than the direct emissions from the power plant.”

The second case, looking at steady continuous emissions is shown in Figure 2 below. The chart compares the thermal forcing from CO2 with that from combustion of the fossil fuels from which that CO2 came - showing the instantaneous forcing from continuous emissions (top panel) and the time-integrated forcing from continuous emissions (bottom panel).

Figure 2 | Results for constant continuous emissions from burning coal, oil, and gas. Ratios of (a) instantaneous CO2 radiative forcing to instantaneous thermal forcing (ΔFCO2 /ΔFthermal), and (b) time-integrated CO2 radiative forcing to time-integrated thermal forcing (IntFCO2 /IntFthermal). The inset in Figure 2a shows that it takes 0.26 years, 0.34 years, and 0.44 years for coal, oil, and gas, respectively, for the instantaneous forcing from accumulated CO2 to exceed the instantaneous thermal forcing from combustion. The inset in Figure 2b shows that it takes 0.52 years, 0.67 years, and 0.88 years for coal, oil, and gas, respectively, for the time-integrated radiative forcing from the CO2 released to exceed the cumulative thermal emissions from combustion. Source: Zhang & Caldeira 2015

Anthony Watts fails logic and arithmetic

I don't know why Anthony Watts can't understand this when he claims to accept that CO2 is a greenhouse gas. What he wrote (archived here), with his usual "claim" headline, was:

Claim: Greenhouse gas-caused warming felt in just months

Anthony Watts / 7 hours ago June 2, 2015

Caldeira It seems in the desperation to erase “the pause” in time for Paris, Ken Caldeira has jumped the shark with this claim. Basically he’s claiming that the heat from fossil fuel combustion is a factor, not just the posited slowing of infrared from Earth’s surface to the top of the atmosphere by increased CO2 concentration.

This headline “Greenhouse gas-caused warming felt in just months” is in contrast to what Caldeira previously said in this Institute of Physics publication saying:

…we find the median time between an emission and maximum warming is 10.1 years, with a 90% probability range of 6.6–30.7 years.

Just why Anthony thinks one finding contradicts the other is a puzzle. If he was driving a car and passed a pedestrian in two seconds, but didn't get to maximum speed for two minutes, does it mean he couldn't have passed the pedestrian in two seconds? In Anthony's topsy turvy world you'd have to say - yes. (Anthony isn't good with numbers - he's shown that on numerous occasions in the past. The simplest arithmetic is beyond his capability. One can rightly argue he is innumerate.)

(Strange that Anthony argues that burning coal, gas and oil doesn't produce heat. He's out on a limb with that one. Very few deniers would dispute the fact. Burning wood produces heat too. If anyone in Chico, California has a gas stove or oil heater or a barbecue, perhaps they can invite Anthony around and give him a demonstration.)

June 2, 2015 at 1:19 pm
But… the earth ain’t warming no mo.
Obfuscation and techno babble to conceal the fact that I am still burning oil to heat my house in bloody June.
It is frigging cold.

Bob Tisdale is another greenhouse effect denying quack who thinks scientists are loons.

June 2, 2015 at 1:20 pm
Do alarmists get loonier around the full moon?
Someone needs to perform a study about the effects of the phases of the moon on the bizarreness of the claims by the CO2 obsessed.

Double on Tundra is the first one to get close to understanding part of the paper, though he's not quite sure:

June 2, 2015 at 1:25 pm
When I turn on the heater in my car, it warms me almost immediately. This is what he means, right? He can’t mean that because I drive my car, I don’t need a heater.

Mark and two Cats thinks that the earth cannot radiate any heat. Even if he rejects greenhouse warming, I wonder where he thinks that all that solar energy hitting earth ends up?

June 2, 2015 at 1:28 pm“The release of CO2 into the atmosphere contributes to the trapping of heat that would otherwise be emitted into outer space.
Heat cannot be emitted into outer space.

Latitude writes more nonsense. Did he bother to read the press release Anthony copied and pasted? It was all about burning fossil fuels to keep "everything above freezing all winter" and more.

June 2, 2015 at 1:31 pm
warming caused by the carbon dioxide……No one knows
So he figured all the heat from heaters in the winter, air conditioneers in the summer…
I don’t suppose keeping everything above freezing all winter counts

The Ghost Of Big Jim Cooley might not understand any climate science but he can't resist posting his "thoughts" at WUWT. This is why WUWT exists. It's a steam valve for deniers:

DaveH lives in a cold climate, I'd say. And he thinks that excessive heat waves, flash floods, worse droughts, famine, severe storms and rapidly rising seas are worth it if it means that the plants that survive will grow a bit more:

June 2, 2015 at 1:37 pm
If you can believe this, it sounds like good news to me. Warm is better than cold and CO2 benefits the planet through the plants so it’s a win-win-win we get the energy from the lump of coal, then we get a warmer planet and finally we get more CO2 for the planet. I’m a bit skeptical that burning a lump of coal really has a meaningful long term impact on warming the planet but this article sounds like coal is a miracle substance.

Admad mistakenly thinks that CO2 is different depending on the source.

June 2, 2015 at 1:42 pm
So. There are at least three different kinds of human-generated carbon dioxide with different properties, from combustion of coal, oil and methane. This is a major breakthrough in chemistry which should earn them a Nobel.

anthonyvioli spouts more WUWT-style nonsense and asks what denier would ever believe any science:

June 2, 2015 at 1:53 pm
And as everyday goes by, not only does it refuse to warm but alarmists become more stupid.
Who actually believes this stuff?
On a side note, don’t worry about measuring temperatures, just follow water vapour.
Its decreasing, for a good reason.

dbstealey, like Anthony, fails simple logic and writes:

June 2, 2015 at 1:53 pm
If warming from CO2 is that quick, it seems to be contradicted by the IPCC’s own claim of long residence times for CO2.

He also misses the point. The reason that there is such a long warming effect from burning lumps of coal is because CO2 stays in the atmosphere for so long, not despite that.

dbstealey tries to recover, and explains that he made that mistake because he can't read a temperature chart:

June 2, 2015 at 2:16 pm
I understand that, John. Maybe you didn’t get my point. If not, sorry about that.
If, as the IPCC claims, the CO2 residency time is a century, then with all the CO2 emitted over the past 50 – 60 or more years, we certainly should have seen some fast-accelerating global warming by now.
But there isn’t any accelerating global warming — there isn’t even any global warming at all! For many years now, global warming has been stopped.
I think whoever said it upthread was right: at this point, they will SAY ANYTHING. Facts and evidence have nothing to do with it. This is all political spin; pablum for the masses.

This is for Smokey (dbstealey) and all the deniers out there who mistakenly think that earth hasn't been getting a lot hotter.

Furthermore, we show that the energy released from the combustion of fossil fuels is now about 1.71% of the radiative forcing from CO2 that has accumulated in the atmosphere as a consequence of historical fossil fuel combustion.I see where this comes from, but even this is an underestimate. Energy generation is around 18TW which is the same as a forcing of 0.035W/m^2. The best estimate for the change in anthropogenic forcing is 2.3W/m^2, so the waste heat forcing is about 1.5% of the net anthropogenic forcing.

However, is you consider that we've warmed by about 0.85K and there is still a 0.7W/m^2 raidative imbalance, that suggests a net radiative perturbation of 3.5W/m^2, so the waste heat forcing is more like 1% of the net radiative effect.

If we continue to emit, then this fraction will continue to get smaller, given that GHGs accumulate in the atmosphere, while waste heat does not.

Watts characterizes the paper as: " Basically he’s claiming that the heat from fossil fuel combustion is a factor, not just the posited slowing of infrared from Earth’s surface to the top of the atmosphere by increased CO2 concentration."

In reality, the paper is saying that the direct heating from fossil fuels is completely insignificant -- the exact opposite of how Watts appears to have read it.

I could see it would be useful for a cost benefit analysis comparing different power sources. As the authors say ""It's important to note that heat emissions from combustion are not negligible, particularly in urban areas," Zhang added. "But carbon dioxide-caused warming is just that much greater. Our results drive home the urgency of cutting emissions immediately."

It's another way of quantifying the enormity of the price we're paying for a short-lived benefit when we could get that same benefit without the GHGs.

There's a Skeptical Science thread from 2010 on this subject, based on Flanner 2009. The estimate there is that the global forcing of anthropogenic thermal energy releases was ~0.028 W/m^2, although regionally higher values were seen (0.39 W/m^2 over the US, 0.68 W/m^2 over western Europe).

But globally, thermal forcing is only on the order of 1 to 1.5% of the GHG forcing. And WUWT continues to be confused.

jmpuss this is just basic science. What is your question. If you mean how much CO2 ends up in the worlds oceans that we emit by burning fossil fuels. It is about half of what we emit. Not for much longer as the oceans are close to saturating and are warming and thus will absorb less and then start to emit CO2. Bert

The cement industry releases about 10% of the worlds atmospheric mercury as well http://www.unep.org/chemicalsandwaste/Mercury/GlobalMercuryPartnership/MercuryreleasesfromtheCementIndustry/tabid/106181/Default.aspx

Back in the seventies one of my Physics lecturers had worked out that a Nuclear powered Electricity Generator only produced twenty times the amount of fossil fuel energy needed to build it. He considered that if you take the unsolved nuclear waste problems into account that these dangerous installations could not pass any sort of cost benefit analysis. Bert

This lecturer used to set us problems to calculate the total heat produced by various methods of electricity generation. The waste heat from coal fired power stations was about twice the useful electricity that was generated. Nuclear generators had a limited lifetime due to inevitable structural failures due to neutron absorption weakening the metal in the reactor.This very smart lecturer then said that the excess CO2 did far more harm than the short term heat release.This is also a problem in so called Fusion reactors. The high energy neutron flux damages the structural integrity of the magnetic containment vessel made of exotic metals. These containment vessels are too dangerous to even dismantle if fusion ever gets up and running. This is the fine print in the fusion dream.If we really want to get it correct we should look at nature and how it harvests the Suns energy in a sustainable way.The bacteria did the experiments for about three billion years by mere trial and error. Without these random experiments we would not exist.

dbstealey also confuses the residence time (mean residence time, or MRT), which is actually quite short -- about 5 years -- with the much longer adjustment time (or response time). The former represents the average time that a molecule spends in a reservoir. The latter represents the rate of decay of a temporary spike that brings concentration in the atmosphere out of equilibrium with the oceans and biosphere. Since most CO2 molecules that move from the atmosphere to the ocean merely trade place with molecules that move in the other direction, a short MRT is consistent with a long adjustment time. The latter depends not on the absolute magnitude of the flows but rather on their average difference. The more generic word "lifetime" also often has been used to refer to either of the two concepts described above, and so ought probably to be dispensed with to avoid confusion.

One thing I don't see in this discussion--maybe I'm just missing it--is the fact that in the long run the net heating from fossil fuel combusion, ignoring CO2 production, is zero. In the absence of other forcings, if it heats the earth above equilibrium temperature, then radiated heat will increase until equilibrium is reached again. How long does that take?

Treesong, direct anthropogenic heating from energy production (nuclear or fossil fuel) is just like any other forcing. Conceptually, it makes little difference if an extra 0.05W/m^2 comes from combustion or from a small increase in solar irradiance. It just happens to be very small compared to other forcings. There still are three more small differences that I can think of.

First, the direct antropogenic heating tends to be localized and since the upwelling longwave power is a fourth power of temperature then a similar total amount of antropogenic surface warming (i.e. increase in average surface temperature) will radiate heat away to space more effectively than the more homogeneous forcing from the enhanced greenhouse effect.

Second, the direct 'forcing' can be instantaneously reduced or suppressed as soon as we cease burning so much stuff up -- quite unlike the much more resilient forcing from the enhanced greenhouse effect.

Lastly, the heat produced from renewable sources such as wind or hydro (though not solar, since this reduces surface albedo) don't generate any extra 'forcing' since all the useful energy that we produce in this way would have ended up as waste heat anyway, through dissipation in the climate system. This is why I restricted the sources of direct anthopogenic waste 'forcing' to combustion and nuclear energy generation.

Treesong, regarding your last question -- How long does that take? -- It would seem to be nearly instantaneous since most energy consumption takes place over land and the surface temperature increase is produced at the very same time as the heat is being generated. Before it gets fully radiated away, there is some time delay over which the extra heat is allowed to disperse and become more uniform, but this time delay promotes rather than it hinders energy dissipation to space since the radiating power is a fourth power of the temperature.

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All you need to know about WUWT

WUWT insider Willis Eschenbach tells you all you need to know about Anthony Watts and his blog, WattsUpWithThat (WUWT). As part of his scathing commentary, Wondering Willis accuses Anthony Watts of being clueless about the blog articles he posts. To paraphrase:

Even if Anthony had a year to analyze and dissect each piece...(he couldn't tell if it would)... stand the harsh light of public exposure.

Definition of Denier (Oxford): A person who denies something, especially someone who refuses to admit the truth of a concept or proposition that is supported by the majority of scientific or historical evidence.
‘a prominent denier of global warming’
‘a climate change denier’

Alternative definition: A former French coin, equal to one twelfth of a Sou, which was withdrawn in the 19th century. Oxford. (The denier has since resurfaced with reduced value.)